Fluid pumps are used within an internal combustion engine system to pump fluid throughout the system. One such fluid pump is the coolant pump. Coolant pumps are often referred to as water pumps because a mix of glycol and water is a common coolant. Commonly, the water pump forms part of an engine cooling system that reduces the temperature of various components of the engine by transferring heat from the components into coolant being pumped through the system by the water pump.
Water pumps are often combined with the fan drive pulley to reduce accessory belt complexity, cost, and bearing power consumption. Some conventional fan-centered water pumps are integrated into the block or front cover of an internal combustion engine. The engine block, or front cover, and the water pump housing define an impeller housing within which an impeller spins. Adjacent the impeller housing is a volute. As the impeller spins within the impeller housing, the impeller causes coolant received from an inlet at the impeller's axial center to enter the impeller and impeller housing, and pass through to the volute at an increased pressure. The increased pressure of the coolant drives the water through the engine cooling system to facilitate heat transfer with the heated components of the engine. The heat transfer from various components into the coolant raises its temperature. The higher temperature water passes through a heat exchanger such as an air-to-coolant radiator prior to returning to the pump inlet. The pressure of the coolant decreases as it passes through the engine cooling system, including a radiator, and reenters the water pump through the inlet at a relatively low pressure and temperature.
The impeller housing of certain conventional water pumps is formed by coupling together two halves of the housing. Typically, one half of the impeller housing also includes a portion (e.g., half) of the volute, and the other half of the impeller housing includes the other portion (e.g., half) of the volute. Such a split configuration of the volute introduces several disadvantages, such as high manufacturing and component costs, seal complexities for suction-side sealing, volute sealing, fan hub structural integrity, length, part-to-part misalignment, etc. Further, conventional fan-centered water pumps, including the inlets and outlets, are situated on one side of the timing drive cavity, which may house a belt system, gear system, and/or chain system. Such a configuration does not utilize the space of the timing drive cavity. Rather, these conventional water pump configurations only add to the length of the engine. Moreover, for such conventional water pump configurations utilizing a timing belt, the length added to the engine is particularly exacerbating, as timing belts are already wider than gears and chains.
Additionally, conventional fan-centered water pumps require a fluid seal between the water pump and the fan shaft and bearings. The inlet of typical water pumps is situated adjacent the fan shaft and bearings. Accordingly, the fluid seal is positioned on the inlet or suction side of the water pump, which can negatively affect the performance of the fluid seal.